This grant proposal is a continuation of the program for the systematic study of psychotropic drugs on the Children's Service of Bellevue Psychiatric Hospital. We wish to evaluate the therapeutic efficacy and safety of drugs that may be potentially useful for these disturbed children, and to correlate behavioral and biological changes on and off drugs. Individual patients will be followed longitudinally to evaluate long-term outcome of drug treatment. The aim of this research is to develop a more rational and safe pharmacotherapy for this population of children. Specifically, in this project the therapeutic efficacy and safety of haloperidol and lithium are compared in hospitalized disturbed children, 6 to 12 years of age, exhibiting a behavioral profile of aggressiveness and explosiveness. These are children who have failed to respond previously to other outpatient treatments. The study is double blind and placebo controlled. It is expected that drug treatment will reduce the above target symptoms and thus improve the child's learning and social behaviors.